摘要:

Contribution to the knowledge of the mechanism of light energy conversion into chemical energy during the photosinthetic process. —A general scheme for the pathways of electron transport in chloroplasts is discussed, in the light of the recent evidence for the existence of cyclic photophosphorylation in vivo. The possible function of cytochrome f is discussed.

ISSN:0017-0070    

DOI:10.1080/11263506309430210

出版商:Taylor & Francis Group    

年代:1963

数据来源: Taylor

摘要:

Germination and growth ofABIES ALBAmill. in different light and temperature conditions. —The results of a research on white fir from different localities are summarized as follows:

ISSN:0017-0070    

DOI:10.1080/11263506309430211

出版商:Taylor & Francis Group    

年代:1963

数据来源: Taylor

摘要:

Growth ofPINUS NIGRA Am. seedlings of different provenance. (Preliminary communication). —Pinus nigra seedlings from different provenance showed, during the first weeks of life, a different growth in height, irrespective of the photoperiod employed. Long nightconditions were, on the whole, more favourable then short night conditions to their height growth.

ISSN:0017-0070    

DOI:10.1080/11263506309430212

出版商:Taylor & Francis Group    

年代:1963

数据来源: Taylor

摘要:

The effects of oxygen and of dinitrophenol on the respiratory activation of potato tuber slices. —It is well known that thin slices from storage organs show, in the first period following preparation and washing, a transition from a low to a high level of metabolic activity. In the potato tuber discs (and similar materials) this transition is characterized by:a)a several fold increase of oxygen uptake;b)an increase of the capacity of dissimilating to CO2the carbon 1 of glucose;c)a decrease of the sensibility of oxygen uptake to the uncoupler 2,4 dinitrophenol(DNP); d)an increase of the capacity of ion and sugar uptake;e)the development of marked capacity of protein synthesis;f)and increase of the activity (as determined in homogenates) of several enzymes involved in the directs oxidation of glucose-6-P or — possibly — in the reoxidation of the TPN reduced by the pentose phosphate pathway reactions. The two latter responses appear with some delay respect the activation of oxygen uptake, which suggested(Marrè et al.)that they are probably rather a consequence than a primary cause of the activation of respiration.

ISSN:0017-0070    

DOI:10.1080/11263506309430213

出版商:Taylor & Francis Group    

年代:1963

数据来源: Taylor

摘要:

Effect of light on uptake by photosynthetic tissues in the absence of co2. —The effect of light and of CO2on the uptake of86Rb and-32P by isolated leaves of Elodea canadensis has been studied. The uptake of both these ions is strongly stimulated by light both in the presence and in the absence of CO2. In the case of phosphate, light stimulates uptake and inhibits the leakage of the ion from the tissues.

ISSN:0017-0070    

DOI:10.1080/11263506309430214

出版商:Taylor & Francis Group    

年代:1963

数据来源: Taylor

摘要:

Effect of light on the uptake, utilization and transport of sugars. —The effect of light on the uptake of saccharides, their incorporation into insoluble fractions and their transport by green tissues has been studied under conditions of complete inhibition of the photosynthetic assimilation of CO2. Such conditions were obtained by means of either an inhibitor of O2evolution (CMU), or by running the experiment in CO2-free atmosphere. When Wolffia arryza plants are incubated with glucose-C14, light stimulates the incorporation of C14into all fractions examined, and especially into the polysaccharides, like cellulose,' which are synthesized outside the chloroplasts.

ISSN:0017-0070    

DOI:10.1080/11263506309430215

出版商:Taylor & Francis Group    

年代:1963

数据来源: Taylor

摘要:

On the metabolism of ethanol in the Pea stem tissues. —The average concentration of ethanol in the growing part of the etiolated pea internodes is of the order of 10-3M. Previous work showed that auxin at growth promoting concentration markedly lowers this level in the excised internodes. This finding prompted a series of investigations on C14labeled ethanol utilization in this material.

ISSN:0017-0070    

DOI:10.1080/11263506309430216

出版商:Taylor & Francis Group    

年代:1963

数据来源: Taylor

摘要:

On the effect of dinitrophenol on carbohydrate activation in higher plant tissues. —Previous investigations on the effects of 2,4 dinitrophenol (DNP) on carbohydrate metabolism in isolated pea internodes and in yeast showed that the increased rate of glycolysis induced by the uncoupler corresponds to an increased rate of the conversion of free hexoses and polysaccarides to hexose phosphates. In yeast about 30% of the radioactivity supplied and taken up as14C labelled glucose, and 20% of that supplied and taken up as glycerol is recovered as soluble sugar and glycogen; this phenomenon is almost completely suppressed by 10-4M DNP.

ISSN:0017-0070    

DOI:10.1080/11263506309430217

出版商:Taylor & Francis Group    

年代:1963

数据来源: Taylor

摘要:

CO2fixation byCUSCUTA EPITHYMUM. —Seedlings ofCuscuta epithymumor filaments detached from the host(Trifolium repens)fix carbon dioxide by mechanism(s) which are, though to a different extent, stimulated by light. Chromatographic analysis of plant extracts that have assimilated C14O2indicates that, in all cases, the radioactivity is detectable in the areas corresponding to the organic acids and the acidic amino acids. No labelling was associated in appreciable amounts with 3-pho-sphoglycerate and the mono- and diphosphate esters of hexoses and pentoses. Such results are substantiated by the finding that cell-free extracts of seedlings and filaments fix carbon dioxide by carboxylating phosphoenolpyruvic acid. It is concluded that, under the experimental conditions, malic enzyme, pyruvate carboxylase and ribulose-1,5-diphosphate carboxylase have little, if any, significance in the fixation of carbon dioxide by the tested species ofCuscuta.

ISSN:0017-0070    

DOI:10.1080/11263506309430218

出版商:Taylor & Francis Group    

年代:1963

数据来源: Taylor

摘要:

On the control of carbohydrate utilization in yeast. —The results of a previous investigation showed that in higher plants the stimulating action of 2,4 dinitrophenol (DNP) on oxygen uptake and glycolysis is accompained by a fall of the level of reducing sugars, due to an increase of their respiratory utilization, and thus — according to every evidence — of the rate of hexose phosphate synthesis.

ISSN:0017-0070    

DOI:10.1080/11263506309430219

出版商:Taylor & Francis Group    

年代:1963

数据来源: Taylor